Alpha Boilers

Alpha 240 and 280 Range

Problem Solution
Boiler on with no demand The DHW microswitch can stick causing boiler to fire up and heat to go round radiators
No high fan speed 'P' models only Check plug M3 on PCB for power, should be 240AC across 17 and 19 for slow fan speed, and 440AC for high speed
Boiler firing for short periods, poor hot water and heating performance

A faulty primary thermistor will affect both heating and hot water, should read 3kohms hot and 14kohms cold


Alpha CB Range


Problem Solution
Fault lights indicate overheat problem

Air pressure switch can break down internally which in turn causes erratic issues with the boiler such as overheating, check resistance through AP switch contacts should be less than 3 ohms when made